1. Field of the Invention
This invention relates generally to improvements in valves, and more particularly, but not by way of limitation, to valve structure employed in tapping tubular members.
2. Description of the Prior Art
The prior art contains a number of teachings of apparatus for securing externally threaded line tap valves to the exterior of penetrable tubing for obtaining controlled access to the interior of the tubing, particularly, for accessing sealed refrigeration systems for servicing. Some of the prior art devices require soldering of the apparatus directly to the tubing which is inherently inconvenient and cannot be accomplished in potentially explosive environments. Other devices are known which are adapted to secure a line tap valve through clamping means to tubing having one specific O.D. These latter devices, however, require that a serviceman have one device of each size for each standard tubing O.D. which the serviceman might encounter on the job. Other apparatus are available which provide means for securing line tap valves to tubing of any one of a plurality of outer diameters, however, such apparatus are generally cumbersome to manipulate, unreliable in operation and difficult and expensive to manufacture.